Safety motor-starting crank.



E. A. MARSH. y SAFETY MOTOR STARTING CRANK.

Patened Dec. 7, 1915.

APPLICATION FILED NOV. 6, 1914.

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EDWARD A. MARSH, OF WEST NEWTON,.MSSACHUSETT-ASSIGNOB TO l'.lI-I-IEl OULFOBJ) COMPANY, 0F BOSTON, MASSACHUSETTS, A CQRPORATION 0F MASSACHUSETTS;

SAFETY MOTOR-STARTING CRANK.

To @ZZ whom 'it may concern Be it known that I, EDWARD A. MARSH,

a citizen of the United States, and resident of `West Newton, inthe county of Middle sex and State of Massachusetts, have invented certain new and useful improveL ments in Safety Motor-Starting Cranks, of which the following is a specicationl The present invention relates to cranks used for the manual starting of internal combustion motors, such as automobile motors, motor boat engines, and in fact all motors which are capable of being started by hand. n

The object of the invention is to provide in connection with a crank of this sort a device for automatically disengaging the crank fromthe shaft of the motor' on which it is mounted in case of a backfire or kick back of the motor so as to avoid danger of injur.

ing the operator. It is well known Athat many injuries have occurred from the sudden and unexpected backward driving of a starting crank vdue to premature ignition in the cylinder of the motor. My invention is designed to avoid all danger of such accidents by causing ther crank to become disconnected from the shaftofthe mot'or upon the instant that the shaftcom'mences to rotate in the reverse direction.

The-nature 'ofthe invention and the manner in which the same accomplishes the object sought and above set forth, are eX-A f plaincd in the following specification in connection `with 'that one of the possible embodiments of thel invention which is 'de' scribed in the following specification-and illustratedin the accompanying drawings.

In the drawings, Figure 1 is a side view of a. motor starting crank with thel hub thereof in section, shown in connection with the safety device or controller and a sleeve4 which is adapted to be placed upon the crank shaft of an internal combustion mo tor or upon some other Shaft which may be engaged with the crank shaft. is a front elevation of the samel with the crank shown as broken' off and the sleeve of the shaft mounting in section. Fig. 3 is a view similar to Fig. 2 but representing the crank asbeing entirely removed. Fig. L1 is a sectional view on line 4.--4 of Fig. 3. Fig. 5 is a perspective view of the member which forms the safety device'or controller of the crank. v

Specicaton of Letters latent.

Fig. 2

The same reference characters indicate the saine parts 1n all the gnres.

Eatented Dec. 7,1915.

Application filed November e, 191e. Serial 10,870,674. i

In the embodiment of my inve'ntonshown q in the drawings, 10 representsa sleeve which is adapted to he slipped upon the crank shaft of an internal combustion motor, or upon the stud shaft which is commonly mounted in automobiles in line with the crank shaft vof the motor to carry the ordinary starting crank or upon 'a shaft-of any otlierdelscription geared or otherwise connecteddi` rectly or indirectly with the motor crank". shaft. This sleeve supports the crank andil vided vin orderto connect thecrankand the controller together in a mechanism which .the controller or Safety device and isprO.l

may be carried and stowed away as a unit.

and may be .mpunted upon any shaft with out requiring to be taken downfa'nd reas. sembled. The sleeve has a keywa-y 1,1. adapted to engage a key on the shaft whereon 'it is mounted tovprevent its rotation aboutithe shaft, and when so mounted the sleeve vis in effect a part of the shaft, and may be considered as representing a shaft. So far as the safety feature of the present invention is `concerned, .the sleeve is unnecessary and may be vomitted altogether and the crank and ,controller applied directly upon the shaft, since the sole function -of the sleeve is to serve as a connector for the crank and controller to enable them-to b e placed upon and removed from` the shaft as a unit; but as to such function said sleeve is a necessaryI part of my invention, and is'so claimed.

The crank is shown at 12 and the handle which is grasped by the hand ofthe operator is shown at 13. The hub 14 of the crank surrounds sleeve 10 and `is made of av suii-4 ciently large diameter to embrace also aring 15 'and the tubular sleeve 16 of the controller. The safety device or controller referred to is a tubular member, which has a sliding fit on the sleeve l0 so that it Imay rotate freely thereon without binding. At one end it has a laterally lor radially projecting flange 17 interrupted by notches 18, and' its other end is intersected ,by One or more slots 19 extending parallel to its axis. The ring' lying the face ofthe ange 17 and 'fitting closely about the sleeve 10 enough to permit rotation of the sleeve within it. Holder 20 is formed .with a. lug 22 4 from which projects a stud 23f adapted to be engaged with a stationary-part ofthe engine frame or bed, or of .the vehicle, or boat, wherein theengine is installed. lSleeve 10 has aliange '24 ,at one end overlying ring 15 and cra'nk'hb 14 to hold the latter against thellange 17 and the holder 20, and on its other end there isdetachably secured by screws 25 an annular retainer 26 which overlaps the web of the holder. l

In the slots 19of the controller are placed rolls 27, each of which lies between the outercylindrical surface ofthe sleeve 10 andl the inner, surface orl bottom of a recess 28 of ring 15, and projects into such recess. TheVU bounding walls of theserecesses are slightly eccentric to the outer surface of the sleeve so as to crowd the rolls against the Sleeve under certain conditions, constituting, in connection with the rolls, clutches of well known character. There maybe one or more o f such clutches, and in the illustrated embodiment of the invention there are three. The inner surfaces of all the recesses 28 are eccentric inl the same manner and to the same degree so that the 'several clutch ele-- ments will act in unison;

In the -notches 18 are also placedvrolls 29 which lie between the inner surfaces of such notches-and the inner cylindrical surfaceof the holder 20. The bottoms or inner surfaces of the notches are inclined or eccentric l to the holder and the rolls 29 are adapted to be gripped therein under certain conditions. There are one or more notches 18'and that the outer surface of outer surface of the ring Y and concentric and that the bottoms of the i rolls 29, each forming a rollerv clutch. To facilitate the gripping of these clutchesl; provide a follower` 30 1n each notch 18 and a springv 31 to press the follower toward 4the roll-and urge the latter toward the shallower end of the notch, the follower and spring being located in the deeper part of the notch. There is also provided a clutch of similar character between the crank and the rin 15, the same comprising a roll 32 located 1n a recess 33 in the crank, such recess having its outer surface 34 eccentric to the outer sur- Aface of the ring 15.

A spring 35 is provided to press the `roll end of the recess where the surface 34 is Vnearest to the ring.

It will be observed from the foregoing description in connection with the drawings the sleeve-10, the

surface of the holder 20 are all cylindrical recesses or notches 28, 18, and 33 are eccentric-to these surfaces.

The mo'de of operation vof the device may nowbe understood, and is as follows. As-

,the clutchrolls 29 clutch rolls 29 in the yieldingly toward the 15 and the innerv 'suming `that the sleeve-.210 is fitted onthe but with freedomcrank shaft' or starting shaft of the motor, and that it ',isvdesired to start` the motor, the operator grasps the handle 13 and turns the crank inthe required direction, this direction being indicated-by vthe larrow in Fig.I 2.

The first eliect produced is to bind the clutch roll 32 between the eccentric surface 34 and the cylindrical outer surface of thering 15 and to cause the ring to turn with'thecrank, The neXt effect is to couplethe ring' with the sleeve 10 by the wedging` of the clutch rolls 2f? between the inclined or eccentric binding surfaces of the recesses 28 and the'cylindrical surface ofthe sleevelO. The sleeve and starting shaft now turnwith thecrank and are thus turned until the motor starts.

If the motor starts in the right direction, p

the sleeve 10 is immediately'driven faster than the crank and the clutch rolls 27 and 32 are rolled into the deeper parts lof their respective recesses ywhere they become disen gaged and permit the sleeve to continue in i rotation and the crank to remain stationary.

But if a backfire occurs and the engine startsl to rotate-in the reverse direction, the clutch rolls become more firmly engaged than be-. fore and the crank would be driven reversely, to the injury of the operator, if it were not for the controlling safety device. This device is in engagement with the'clutch rolls 27,"there being a segment of the'device adjacent to each roll, as vclearly appears from Figs. 2 and 3; 'In the normal rotation of the crank the controller turns with it and-the clutch rolls-29 travel alongin'side of the j iolder 20, but in case of a backfire in the motor l' and reversed'rotation of the shaft, the first back movement of the controller'causes to be gripped`between the stationary holder 20 and the outwardly in clined eccentric inner surfaces of the notches 18, preventing rotation of f the controller.

vThis effect occurs instantly'because the spring followers tend always to hold the .position where they make contact with the opposed clutching surfaces, so that the clutching effect occurs as soon as any movement ofthe controller .takes place in the clutching direction. THe

occurs instantly land before the crank has can not be trans-I crank from the shaft,'

moved backward far enough to give even a slight shock to the hand or arm' of theoperator. It will vention consist of the combination with a shaft, of a crank and a controller both' mounted loosely upon the shaft, that is, vso that they may turn about the same, a clutch- 'ing device which is operated automatically when the crank is turned in the starting difA ters Patent is troller to the shaft so that both the con-v l rection to couple the crank and the controller and the shaft'are caused to turn with the crank when the latter is started li'n rlitat ing direction or forward direction, and van other clutchingl device operating inconnection withgaI stationary holder to arrest the controller upon reverse rotation of the shaft and thereby cause disengagement or unconpling of the first clutch, although permit-v ting the controller to revolve freely in the -forward directionf The sleeve 10 -may be omitted and the vcrank and safety device mounted directly upon the shaft,the outer surface of 'which then becomesthe clutching surface. wherewith the primary clutch rolls 27-are gripped bythe inclined interior surfaces of the crank hub. But whenl the device is mounted on the shaft, the sleeve becomes'as much a part of the shaft as though it were an integral part thereof, and for the purposes of this .invention and of thefollowing claims, the

sleeve may be considered as representative -of the shaft, wherefore I intend the term shaft as used in the following claims to coverthe sleeve as well as a shaft, and to cover also-a combinationl ofthe shaft with the sleeve mounted upon it.

' Mysafety-crank above described is a compact unit which may be assembled at the factory and thereafter shipped `and packed without becoming disassembled, and it may be mounted upon any shaft in place of the crank commonly provided in exactly the same way. and with the same ease that a o ne piece crank is so applied, so that any one,1n cluding persons having no understanding of the inner construction and the mode of operation of my crank may apply it to the motor. I have intended to embrace within the term crank as used in the foregoing specification and the following claims, any element or device having the function of the starting crank of an automobile or other internal combustion motor, and whether the same is in the form of an arm or has a multiplicity of arms, such as a disk or a fly wheel. 4It is, of course, to be understood that while I have described the clutch elements as rolls and the spaces 19 in the controller as slots, I have used these terms only descriptively and without' ylimiting significance. Any lele'- ments and constructions which perform the be understood fromA the foregoingl description' that the main elementsof the in and are intended-to be embracedwthin the 'descriptive terms used. For example, 'in

place of cylindrical clutchfrolls I inight use openings 19 as slots, 'suchopeningsmould `be clutch element might-be employed.

What I claimand desire to'secureby Let- 1. A starting cran'krniechanism lfor internal combustionl motors, comprising incombination with a shaft, a-"crankmounted on said shaft and rotatable about the same, a

7o balls or .spheres and in place l'of forming the -made as .holes or perforationsgonl -suig y ciently large to contain freely/w atever l clutch element betweenv said crank and'shaft constructed to engage when relative rotation between the crank and shaft takes place in one direction, and to be disengaged-when such relative rotation takes place in the opv posite d1rect1on, a controller also rotatable` l about the shaft and having an element eX-- tending axially between thefshaft and the t crank and beside said` clutch element, and

around which the crank is-rotatable, a relatively stationary holder, and a clutch ele-,A 'i i ment between said holder and the controller.

constructed to` become engaged when the controller is rotated in thedirection opposite to the normal direction ofv rotation of the shaft. f

2. A safety starting crank mechanism comprising, in combination with ashaft, a crank and a controller mounted to rotate vabout said shaft, a stationary holder with respect to which said shaft, said controller, and said crank are all rotatable, a clutch betweenthe crank and the shaft constructed to couple the crank to the shaft when the crank is turned relatively to the'shaft in the` lverse ofthe normal directionand the controller is held stationary.

3. A safety Astarting crank mechanism comprising, in combination with a shaft, a crank and a controller mounted to rotate about said shaft, a stationary holder with respect to which said shaft, said controller, and said crankl are all rotatable, a clutch between the crank and the shaft. ccnstructed to couple the crank to the shaft when the crank is turned relatively to the shaft in the direction of vnormal rotation of the shaft,

' direction of normal rotation 4of the shaft, 'l and to `be disengaged when the relative rota-- tion takes place in the opposite direction, a

clutch between the controller and-the holder' constructed' to be engaged when the controller is rotated in thedirection opposite to the normal rotation of the shaft, and to be disengaged when the controller rotates in 'the opposite direction, said -controller yhaving a tubular portionextending between theshaft and the crank, and upon the exterior of which said crank hasits bearing, said portion being provided with an aperture through which the first-named clutch "element extends into engagement both with the shaft and the cranl 4. A safety starting crank mechanism for internal combustion motors comprising," in

combination with a starting shaft, a crank, a controller, and a holder all surrounding said shaft, the said crank and controller being rotatable about the shaft, and said holder being stationary, said crank and con troller constituting two rotating elements,

one ofwhich is provided with. a segmental' portion'having a slot and extending between the shaft and the other of said elements, and lthe said other rotatable element having a clutching surface, a clutch roll contained in saidslot betweenthe shaft and said clutching surface, and a second clutch roll intertively to thesleeve, to the holder, and to each other, a clutch between the controller and .the holder to permit rotationof the controller in one direction relatively to the holder and prevent such rotation in the opposite direction, anda clutch roll between the icrank and controller 'and the sleeve, constructed to be crowded lagainst the sleeve .when the v'crank is turned in the direction in y which rotation of the controller is permitted, said controller` being constructed and yarrange'x to release the second named clutch when the sleeve is turnedin the `direction inv which rotation vof the controller is prevented, the sleeve having means for holdingfthe parts of the apparatus in coperativevrelation.

6. A safety starting crank'mechanism for internal combustion motors, shaft, two rotatable' elements surrounding said 'shaftand adapted to rotate relatively to the shaft, one of said elements being av a con,

starting crank and the other being troller, a clutch member interposed between one of said elements and the shaft and constructed to couple them together when said element is tlrned in one direction, an extension on the other of said elements lying adjacent to' the shaft and in position to bear, when relative movement between the shaftganditself takes place, on said clutch member, a stationary holder adjacent'to the controller, and a clutch device between said holder and controller constructed to permit: rotation .of the controller in the direction of normal rotation'of the shaft, and to prevent movement of the controller inthe opposite direction. Y 4

In testimony whereof lI have affixed my signature, in presence of two witnesses.

EDWARD A. MARSH. Witnesses:

C. F. BRowN, P. W. PEZZETTI.

lcomprising a 

